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LI special - swansong project?

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Re: LI special - swansong project?

Postby dickie » Sun Nov 15, 2020 9:19 pm

Warkton Tornado No.1 wrote:What a shame that the actual manufacturer cannot get these 'boxes consistently good enough. I've known of them too soft & wear out quickly or too hard & snap teeth off.

The profiles depicted are very rough & obviously inaccurate.

If you can machine on a lathe, or get access, far better to make your own from two or more clusters. Get beneath the hardened parts (grind off unwanted sections) & shrink fit relevant portion (usually fourth or third/fourth from a donor cluster) on to the modified cluster is one of several methods......

You're probably right, but I'm an electrical engineer with a bit of mechanical aptitude. While I know what you mean, I'm pretty confident that I'd balls it up. :lol:
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Re: LI special - swansong project?

Postby dickie » Thu Nov 26, 2020 10:01 pm

So, I sent the box, layshaft and selector back to AF.

Ben checked it over and found that 3rd gear wasn't machined deeply enough, which was no big surprise as the loose gear teeth were hitting the root of the cluster.

I was also having trouble shimming the box and worked out that I needed a 1.6mm or maybe even 1.4mm. I guess this was an issue with the layshaft. So he supplied 3 x 0.2mm shims to go under the output bearing thereby pulling the layshaft away from the end-plate.

Image

He reckoned these would mean I needed a 2.0mm box shim, but I actually needed 1.6mm.

Here's what I mean in case I was too rambling in my explanation.

Image

Anyway, the box is now really slick with 0.1mm clearance and shifts very nicely.

Those new plates for the output shaft bearing from MB seemed like a nice idea, so I decided to give one a try and I like them. Tiny gap of 0.05mm but as long as there's a gap, that's ok.

Image

Some dealers are great and even though AF are pretty sh1t at answering the phone, they come up with the goods and great old fashioned honest customer service when you need it.
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Re: LI special - swansong project?

Postby dickie » Thu Nov 26, 2020 10:11 pm

Image

Ramp cut off the end plate and using adjustable type.
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Re: LI special - swansong project?

Postby Storkfoot » Thu Nov 26, 2020 10:56 pm

What did AF do to the gearbox to rectify the problem with third gear please?
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Re: LI special - swansong project?

Postby dickie » Thu Nov 26, 2020 11:30 pm

Storkfoot wrote:What did AF do to the gearbox to rectify the problem with third gear please?

Sorry, I should have said.
He simply gave me a different cluster that was machined properly..

The AF 4speed close ratio box is Indian gp200 but with 1st and second replaced with pacemaker loose gears. So I guess it's just the same as Indian gp200 Christmas tree.
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Re: LI special - swansong project?

Postby dickie » Fri Nov 27, 2020 12:51 pm

Next problem. Trying to align front and rear sprocket. The rear one is 1.0mm higher than the front. I can't get rid of this by playing with clutch shims. So, do I add 2 x dished washers to the front? Or I could leave out the rear one completely and bring it into line?

Alternatively, I could grind 1mm off the clutch sprocket. This would be a pain in the arse to do with files and a stone.

I might nip along to my mate's now and do them on his lathe.

Image
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Re: LI special - swansong project?

Postby dickie » Fri Nov 27, 2020 1:27 pm

Had a word with my mate and we decided it was better to shim up the front rather than risk damaging the sprocket and basket, as the basket is hardened.

So I found that clutch sprocket shims are just too small to fit over the drive end of the crank by about 0.1mm. 2 minutes with a round file and it's perfect. Now aligned within 0.1mm lower at the clutch. Happy with that.

I should add that part of that decision was that I checked the new 20 tooth front sprocket against a selection I have and found that it was about 1mm lower than all but one which was a 19 tooth from the same supplier.

I decided to fit behind the dished washer to allow easier oil path onto the drive bearing.

Image
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Re: LI special - swansong project?

Postby Warkton Tornado No.1 » Fri Nov 27, 2020 7:13 pm

I hope all of the quality issues have been fished out now :!:

Just be very wary that there is not the slightest hint of clutch drag as my belief is that a lot of Indian produced 'boxes cannot tolerate that & teeth can snap just by selecting first gear. Don't suppose you have access to a Rockwell (or any other type) hardness tester? Not that I have :? It's no consolation when you look @ the grain structure of a tooth root & suspect brittleness & a dealer says that they think different.....
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Re: LI special - swansong project?

Postby dickie » Fri Nov 27, 2020 8:47 pm

Warkton Tornado No.1 wrote:I hope all of the quality issues have been fished out now :!:

Just be very wary that there is not the slightest hint of clutch drag as my belief is that a lot of Indian produced 'boxes cannot tolerate that & teeth can snap just by selecting first gear. Don't suppose you have access to a Rockwell (or any other type) hardness tester? Not that I have :? It's no consolation when you look @ the grain structure of a tooth root & suspect brittleness & a dealer says that they think different.....


Quality issues sorted? I doubt it. I really think I should have bought a UNI casing, although I've heard there are issues with them too.

Anyway, the clutch is another story which will (probably) be resolved tomorrow.....
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Re: LI special - swansong project?

Postby dscscotty » Sat Nov 28, 2020 8:08 pm

Regarding any concerns around the AF 4 speed and its strength, we run them in race engines up to 38bhp, without issue, we did loose a tooth off first gear at Croft this year on our 4e but the gearbox had been in for 3 seasons won a championship along with a 6 hour endurance race with 3 BSSO racers on board, the 3rd gear issue has come to light before, but easily sorted,
Here's one being put through its paces in a 38bhp RB22, revving to about 10k- #1 DSC RB2

https://www.youtube.com/watch?v=6FHwOi3qIgk&t=322s
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Re: LI special - swansong project?

Postby dickie » Sat Nov 28, 2020 8:39 pm

dscscotty wrote:Regarding any concerns around the AF 4 speed and its strength, we run them in race engines up to 38bhp, without issue, we did loose a tooth off first gear at Croft this year on our 4e but the gearbox had been in for 3 seasons won a championship along with a 6 hour endurance race with 3 BSSO racers on board, the 3rd gear issue has come to light before, but easily sorted,
Here's one being put through its paces in a 38bhp RB22, revving to about 10k- #1 DSC RB2

https://www.youtube.com/watch?v=6FHwOi3qIgk&t=322s


If it can put up with that, it can put up with me popping out for a full english once a fortnight. Even if I am trying to ride at my mate's pace on his GS750.
Anyway, my attempt at a cheap 6 plate clutch failed, but I'll have a very good 5 plate once I've got some new steels. I've oddly got loads of 1.0mm, 1.2mm, bent tangs and all that nonsnese but no standard 1.5mm ones.
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Re: LI special - swansong project?

Postby Warkton Tornado No.1 » Sun Nov 29, 2020 2:27 pm

dscscotty wrote:Regarding any concerns around the AF 4 speed and its strength, we run them in race engines up to 38bhp, without issue, we did loose a tooth off first gear at Croft this year on our 4e but the gearbox had been in for 3 seasons won a championship along with a 6 hour endurance race with 3 BSSO racers on board, the 3rd gear issue has come to light before, but easily sorted,
Here's one being put through its paces in a 38bhp RB22, revving to about 10k- #1 DSC RB2

https://www.youtube.com/watch?v=6FHwOi3qIgk&t=322s


I'm pleased that the CR 'boxes appear to be sorted now :D

The one I had that failed, lost teeth off first gear, first time out in about 2013, so could have been one of the earlier versions of their "revised manufacture"

It's fair to say that we are often Guinea Pigs for early production. The very first batches were reported to be way too soft by Steve Ives.....
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Re: LI special - swansong project?

Postby dickie » Tue Dec 01, 2020 10:16 pm

I wanted to make a cheap, good quality 6 plate clutch from "normal" lambretta parts rather than cassette type so that I could modify easily and also just because I like farting about with stuff like that.

So, I've been keeping an eye out for cheap parts on ebay and Facebook and gathered together; stratos extended spider, stratos deep crown wheel, some unknown make deep pressure plate. No science went into this at all, I just figured getting bigger stuff would have more room and I'd be able to squeeze 6 thin 2.6mm plates in.

Image

Image



Well, I couldn't. Or I could if I'd used 1mm steels right through and a 2mm top plate, but it wouldn't have been very robust, nor do I really need 6 plates. I just wanted 6 so that I could use really light springs.

Anyway, I've ended up using 5 x 2.6mm corks, all steels are 1.5mm and the top plate is a nice thick 3mm one. BGM springs are my favourite because they have a longer free length but when compressed have an appropriate preload. This means that the force at the lever doesn't increase as much as the lever gets closer to the bar.

So, as a result, I've got loads of clearance, so no drag (specially for WT1).
Normally I just build it all in one go, but this time I decided to try building without springs which turned out to be a good way of getting it nicely set up and operating smoothly. Then springs right at the end when it's all good.

You can see about 2mm clearance here..

Image

It's not a super powerful motor and the gearbox has a high ratio, so I reckon this will work.fine. if not, I'll swap one or two plates for 3.5mm ones.

Image
Last edited by dickie on Wed Dec 02, 2020 1:49 pm, edited 1 time in total.
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Re: LI special - swansong project?

Postby Rich Oswald » Wed Dec 02, 2020 11:54 am

You can see about 2km clearance here..

2km clearance...... that's one hell of a space :lol: :lol: :lol:
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Re: LI special - swansong project?

Postby dickie » Wed Dec 02, 2020 1:12 pm

Rich Oswald wrote:You can see about 2km clearance here..

2km clearance...... that's one hell of a space :lol: :lol: :lol:


Ah yes, you have a point. Maybe I'll need longer springs. 2mm in case it isn't obvious what I meant :lol:

Anyway, I'm going to pull it back out as I'm not happy about the spot welds on the pressure plate. I'll go and TIG them as I'm nervous they'll pull apart.

Image
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Re: LI special - swansong project?

Postby Warkton Tornado No.1 » Wed Dec 02, 2020 1:51 pm

That all looks good & the methodical approach will be worth it :D

I had good results with the scootRS six plater, but it relied upon measuring spring gauge & fully compressed length to get it functioning well. It slipped a little if I ragged it (ported Rapido, TS250 piston 71 x 61, homemade long rear cone, ground clearanced clubman with only a 38 mm entrance 'U' pipe, 25 mm bleed tailpipe into a silencer) which was cured by the ATF (sorry to keep going on about the stuff, but I fit it in anybody's 'boxes now :oops: )

Simply because I had (& still have!) leftover CamLam thin plate/cork clutch components, I initially tried them in a ported TS in only a five plate guise that was said to be about 30 BHP but no idea of torque. I've since rebuilt that same, very tired, over ported TV200 block with a more radical 70 x 60 TS setup that has porting direct from the crankcase to the top, boost port. I couldn't faff about with those 'Cadbury's chocolate finger' ports so common & just put the ring pegs where I wanted in the DT250 piston to allow for a mono-port of the same duration as main transfers.

For that reason, I thought it best to try six plates with the only changes being the bent up tags.

The owner tested it & he only knows one way of riding, so I know the clutch is great as the bike absolutely flies. He can have it back when he's paid for the work/parts.... ;)

So, excuse the waffle, but with careful selection & a dry build, a very useable clutch can be had using conventional type products.......with ATF. Did I mention that :?:

Oh! Mustn't forget! A dry, meticulous build is the way in which I discovered that the TS engine I speak of could take six plates, rather than only five as previously squeezed in. The issue of lost space was down to the Indian clutch bell centre (sprung pressure bell) was deflecting due to the pressure of the springs. It was acting as a spring itself! I fitted an old Innocenti bell & gained the additional space in doing so.Absolutely drag free clutch! (I wonder if it has anything to do with the oil I use? :roll: )
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Re: LI special - swansong project?

Postby dickie » Wed Dec 02, 2020 5:49 pm

I might give ATF a whirl. Are there different types?

Anyway my mate put some little tack welds on the outside edge to stop the top plate peeling away. Probably not an issue, but was niggling me.

When I put it back together I was checking that the welds didn't protrude so far that they stopped the clutch springs fully extending and found that not only would the welds stop it, but the top plate itself was sufficiently close to the circlip as it could stop it before the welds came in to play. I had to file the end of the circlip to get it in, so the groove in the stratos spider mustn't be as deep as standard; I tried 3 circlips and all were the same.

So I ground a chamfer onto the top plate. I'm not convinced I needed to do this as I think it was partly caused by my cheap clutch compressor pushing the clutch down and releasing it unevenly. I did it anyway to be sure.

Image

A lot of time and effort for a 5 plate clutch!
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Re: LI special - swansong project?

Postby Warkton Tornado No.1 » Thu Dec 03, 2020 1:32 pm

dickie wrote:I might give ATF a whirl. Are there different types?



There are different types, but Dexron III is what I had spare from a Bongo ATF change. TBH, what I drained from the auto box was so squeaky clean, that I filtered that & used it on the first couple of tentative trials before I started using the spare new stuff. One engine was a full on Group Four with Japanese alloy clutch, which, if you think about the abuse of the deliberate feathering of the clutch @ hairpins etc with the high, CR 'boxes fitted, makes ATF likely to be more suitable. I've witnessed fellow racers cooking their clutches on the line when starts are delayed using conventional oil :roll:

If you can't get it in just a litre bottle, I'll send you some new(!) to try via Herpes or whatever :D
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Re: LI special - swansong project?

Postby dickie » Thu Dec 03, 2020 1:52 pm

Warkton Tornado No.1 wrote:
dickie wrote:I might give ATF a whirl. Are there different types?



There are different types, but Dexron III is what I had spare from a Bongo ATF change. TBH, what I drained from the auto box was so squeaky clean, that I filtered that & used it on the first couple of tentative trials before I started using the spare new stuff. One engine was a full on Group Four with Japanese alloy clutch, which, if you think about the abuse of the deliberate feathering of the clutch @ hairpins etc with the high, CR 'boxes fitted, makes ATF likely to be more suitable. I've witnessed fellow racers cooking their clutches on the line when starts are delayed using conventional oil :roll:

If you can't get it in just a litre bottle, I'll send you some new(!) to try via Herpes or whatever :D


Thanks, but I gave a herpes a try once before and it wasn't for me.

I can see it pretty cheap for 1L one Ebay.

I don't suppose it would make any difference that it's a brand new gearbox and clutch, would it?

For the last couple of years I've been using maxima oil in gearboxes as I've found it gives much better gear changes.
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Re: LI special - swansong project?

Postby Warkton Tornado No.1 » Thu Dec 03, 2020 4:19 pm

dickie wrote:
Warkton Tornado No.1 wrote:
dickie wrote:I might give ATF a whirl. Are there different types?



There are different types, but Dexron III is what I had spare from a Bongo ATF change. TBH, what I drained from the auto box was so squeaky clean, that I filtered that & used it on the first couple of tentative trials before I started using the spare new stuff. One engine was a full on Group Four with Japanese alloy clutch, which, if you think about the abuse of the deliberate feathering of the clutch @ hairpins etc with the high, CR 'boxes fitted, makes ATF likely to be more suitable. I've witnessed fellow racers cooking their clutches on the line when starts are delayed using conventional oil :roll:

If you can't get it in just a litre bottle, I'll send you some new(!) to try via Herpes or whatever :D


Thanks, but I gave a herpes a try once before and it wasn't for me.

I can see it pretty cheap for 1L one Ebay.

I don't suppose it would make any difference that it's a brand new gearbox and clutch, would it?

For the last couple of years I've been using maxima oil in gearboxes as I've found it gives much better gear changes.



I started trying with different grades of oil because I've contracted to various Motorsport teams in my time & been 'given' (ahem!) samples by kind storemen. Anything from Mobil 1 (0 - 40w) to Penzoil & other stuff you see in catalogues.

However, being aware from the 70's that Bantam racers had only three gears & used ATF because they had no choice other than slip their clutches to the point of abuse, I figured that it's worth a try.

It works, of that I have no doubt.

However, since then, I've heard Bantams nowadays also ccontinue to use ATF, but some also use "steel on steel" with no friction (cork) @ all. I haven't got around to trying that (yet) but immediately you can imagine the number of plates that can be fitted as a consequence :!:

This concept certainly needs further investigation......Kerist! What if it worked? Imagine the impact upon all the sellers of 'our' performance clutches!

Who is brave enough to try? :?
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